Today we are going to install a Torpedo Stainless Steel shaft into our Walbro 1048 carburettor.

The Torpedo Stainless Steel throttle shafts replace the factory brass shaft in the Walbro carburettor that is prone to breaking. The Torpedo shafts feature a precision cut out on the opposite side of the butterfly disc to allow more flow through your carburettor. To assist in securing your throttle arm, both ends of the shaft are threaded to fit a M3 bolt. No longer will you need to rely on a tiny grub screw to secure your throttle arm.

Like usual, simply click on the ‘more…’ button below to see the tutorial.

The first step in replacing the shaft, is to remove the c-clip from the factory brass shaft. You could use a number of different methods to remove the clip, most involved a flat blade screw driver. We tend to use a tiny flat blade to pull the clip out backwards. If you don’t have a small flat blade, you could use a larger one to push it out.

Now that the c-clip has been removed from the shaft, we need to remove the butterfly disc from the inside of the carb. Once removed we can pull out the shaft.
This step is super simple, simply unscrew using a phillips head driver.

Here is an almost pointless photo of the butterfly removed from the shaft!

Now it’s time to pull the brass shaft out of the carb, this can be a little tricky and might need a little bit of force.
The photo below shows you the position you need to have the shaft in to remove it.

Now that the shaft it removed, you can pull the spring off.

Here is probably the most tricky part of this tutorial, you need to remove the throttle position wheel from the shaft.
To make this easier, pop it into a vice and use a flat blade screw driver and hammer to chip away the excess brass that secures it to the shaft.
It’s been press fitted, so once we chip away the edges it pill pop straight out.

You should now we left with a throttle position wheel and no shaft!

Now we simply need to screw the position wheels onto the new shaft using some thread locker.

Right so now the wheel is back on the new shaft, you can put the spring back on!

Using a little bit of oil of some type insert the shaft back into the carb, again you might need to use some force to push it past the idle needle thread.

Now that the shaft is back into the carb, we need to replace the c-clip!

Use a flat blade screw driver to push the clip back into place!

Now the clip is back in place, position the spring so that it has tension, you just push the leading edge of the spring clock wise so it locks back into the carb.
You should now have a functional carb that is spring loaded.

Using some thread locker again, screw the butterfly back onto the shaft. It will only really fit one way. (Point the cut out of the disc towards the needles and screw it on)

Bingo! We have now replaced the standard brass shaft with an upgraded stainless steel shaft!
You can now install your throttle arm 🙂